Telephone-receiver.



S. P. GRACE & R. A. L. SNYDER.

TELEPHONE RECHVER. APPLICATION FILED OCT. 17. 1910.

1,161,856. Patented Nov. 30, 1915.

- magnet, the diaphragm being supported in' close proximity to one of the poles of the .eleetro-magnet, and the permanent magnet a PATENT-Y TELEPHONE-RECEIVER; I

To all whom-itmayfihcrjn: I

Be it known that we,

efliciency is secured. H

An ordinary type of telephone receiver comprises .as its principal elements an 1318C, tro-magnet, a diaphragm, and a permanent creating the initial magnetic field in the air gap between the pole and the diaphragm.

This initial magnetic field is then caused to be varied by and in accordance with the voice currents flowing in the coil of the elec tro-magnet, the diaphragmbeing caused to vibrate by the variable attractive force which is exerted directly upon it through the air gap, and thus producing sound waves, which follow closelythe undulations of the voice currents. Although it is usual to'employ a i vpermanent magnet for the purpose of -de- 'veloping the" initial magnetic field, an .electro-magnet may be employed for' 'the-same' purpose; or a single electro magnet maybe employed, the coil of which receives a steady and also receives the-voice cllll' ent s fsupr' posed on the steady current.

The generaltype' of telephone receiver-QT" t which our invention particularlyres w lates, differs from this ordinary type" principally' in] having the diaphragm placed;

away fromthe pole orpoles of the electro magnet, the diaphragm however being con nected to an armature by a l'ever' which"cOni-'., municates the movements of. the.armature to j the diaphragmia- The armature.fiis flmade heavier than the ordinary receiver (ha-- phragm; consequently the, vibratory move ments of the armature-dueto the-voice cur rents' in the coil offtheelectro-magnetare of small amplitude, the objject fof the connect- Specification brte'tters Patent,

SERGIUS P.- GRACE and RIO ARDA. 'L'. SNYDER, citizens of th'e United States, residing at Pittsburgh, in the State of Pennsylvania,haveinvented a newand useful Improvementin. Telephone-Receivers, of which the following isa full, clear,

-concise," and exact description.

Our invention relates in general .to apparatus fen-transforming electric waves into mechanical vibration, and more particularly. to' aloud? speaking 1 telephone receiver; its objectis to simplify and improve the construction oil such apparatus, whereby great-- v. of the ordinary telephone? receiver,

approgimately dine its center of gravity. y'Each end-ofqtheiarmature'lies inn proximity to onej of-the pole-pieces ofa two "over its bearing, ,Bythis construction equal normalattractive.- force" betwee1rit free ends of the armature; and the poles v able, maybe arranged ,-to bear against is armature "on; eith How of current which creates the initial field .I

suitable" for contrellin' with a part broken a ayof?the alnl.ature.

gcombrisesflasfits'ipr p l fielements a;

"rat iited'itov'. 30, 19115 Application filed October 1 '1e1 0. seri l N $7,373.]

ing lever being to multiply the? movement of the armature in "the diaphragm The armature,beingofzheavier mass than it is pos-' sible to make the diaphragm, is however;

acted upon by the; electro-magnetf with 3 1 greater force, and "the netresult is "that; a

7 greater movement is f imparted to the :dia

'phragm than is possible where thedia+,

Phrag js directly act d' n as ilrthe case? a 'Altelephlone reeeivergconstructed m5; an-i ,-W our inventio is provided; With; n altmature-mdunted'on bearing lying coil electric-magnet, and an initial 'magnetiz ing forceis provided for whichpolarizes the two pole piece's' alike. [The electro-mag net ispreferab.ly of,thehorseeshoe type, the are mature being pivoted 'midwaybetween the free poles thereof and the-two ends of the v armature lying close'to said poles. The ini-; tial magnetizing force, for 'th'e armature is generated by a magneawhich may be either: i

permanent orelectrmfone ,pole of thismage net being presented ,to-"the yoke- (Sf-the elec-i' tro-magnet, and the otherv t o"fthe armature.

midway between its. ends thusdirectly:

librium, a pairof s rings; preferably adjust r ide' 'eft tal b e 1s ii-it r i n a 'i'eii Fig. 2:is'"anjendlelevat on'ofthestructure ishowthebea ing l 1 V 'e' i 'r-I- e e z et" *n IOP' iating ,electro agnet Q, jan armature :3, "and;

' "Thefjarmatureis pivoted 'Y'b a ax s; fte l;

. tween the axis 5 that the turejnay be caused to. take a position in which theair gaps between its ends andthe pole pieces 10 11 of the electro-magnet are approximately equal; preferablythe armature is built up of laminated iron and it is rigidly connected by a very light but stifi' arm 12 to the center of the diaphragm 4, the outer end of this arm being secured to the diaphragm by a small screw-13. As the mass of the armature is an element c0ntrolling the pull of an electro-magnet thereon, it is desirable to employ a comparatively large armature and to employ springs to overcome the inertia of the armature and the to normal the use of a construction, the diaphragm may be given a parts opera-ted thereby in return position. By armature and vibratory movement corresponding to'the frequency of sound waves.

The diaphragm, may beheld in any suitable manner. As shown it is secured in a cupped part 14 of the frame and held in place between gaskets 15 by a cap 16. This cap has an orifice provided with a hornjl7, the outer end of which is supported by a forked plate 18 fastened-to the base of the frame by screws 19. The diaphragm is preferably of mica and referably is so mounted that it lies in a p through the axis of movement of the armature, the objectbeing to permit free movement of the diaphragm.. tain very light weight without sacrificing rigidity, the arm 12 is preferably tapered away from the armature.

Heretofore diaphragms have-been oper-' ated by the armature of electromagnets, but the connection between'the diaphragm and the armature has been angular, and the diaphragm will have, in addition to the move-. ment corresponding to those of the armature, an added movement; in other words, the movements of the diaphragm willnot correspond exactly to those of thearmature.

In the construction shown and described herein, the armature and diaphragm are so arranged relative one to the other, i. e., the diaphragm in plane parallel with and passing through theaxis of movement of the armature, and so connected that the movements of the armature modified, or added to be included in a induction coil 28 cuit29'to a second induction coil 30, the pritwo secondary ane WhlCh passes In order to ob receivers would be will not bechanged, in transmission to the diaphragm. The movements of the.arma-' ture and diaphragm vary only in amplitude, the latter being a greater distance from the common center of movement of both. As the arm extending from the armature to the diaphragm should be attached centrally to the latter, the arrangement of the diaphragm at an angle to a plane coinciding with the faces of the poles of the electromagnet permits of a more compact arrange ment of the parts and a simpler form of arm.

The operating electro-magnet 2, comprises a yoke 20 and two cores surrounded by the coils 21 22. It is held in place in the frame by screws 23 by which its position may be adjusted. The energizing magnet 1 may if desired be prdvided as shown with coils 2 1, which would be included in a local circuit. One of the poles 25 of this magnet extends underneath the yoke 20 of the electro'-magnet 2, While the other pole 26 "extends over the armature 3. .The magnet 1 is adjustably secured to the frame by clamping plates 44 and screws 45. The normal magnetic circuit extends from pole 25 of magnet 1 t0 yoke 20 and through two cores of the electromagnet in parallel to the poles 10 and 11, the armature 3, and from eitherend thereof to the middle and thence to the other pole 26 of electro-magnet 1.

The coils 21-22 of electro-magnet 2 may circuit 27 extending to an and thence by way of cirmary winding 31 of which, is included in a local circuit with a' transmitting telephone 32 and a battery 33. This induction coil 30 may have one or more secondary windings. In the system of circuits shown there are windings, one of which, :34, is included in the'circuit'29 referred to and the other of which, 35, is included in a circuit'36, which may be extended to a telephone repeater '37, the local circuit 38 of which includes a battery 39 and .one winding of an induction coil 40. The other winding of this induction coil is included in a circuit 41 leadmg to another loud speaking receiver 42. There-may be, as shown, a conat a central station,

tions. more. or less at a distance-from the transmitting station. .VVhere the distance is great, the arrangement of circuits leading to the receiver 42 would be preferable, wherein the telephone repeater 3 assists to increase the volume of current in the receiver. At shorter distances, repeater would not be needed.

The operation is as follows: A person talking into the transmitting telephone 32 while the loud speaking located at various stasuch telephone will causevoice current to traverse the cirfor connecting the armature to the receiver cuits leading to'the coils 21 22 ofthe loud. dlaphragm. 7V

speaking receivers at the various outlying 2. In a telephone IGCGIVBI, the'comb-inastations. .At any given moment when curtlon of two separated magnetic poles of a rent is flowing in these coils, there is an inmagnet forming opposite polarity, an eleccrease in the attractive force at one pole, vtro-magnet having its cores forming consay pole 10, and a corresponding decrease tinuations of one of said poles, an armature in the attractive'force at the other pole 11. lying between the ends ofthe cores and the The effect on the armature is thus. to rotate free pole of the magnet and having a pivit on its pivotal bearing in the direction of otal support intermediate its. ends, the axis the hand of a clock and the diaphragm 4 of movement of the armature being in a is moved or bowed out'slightly to the right plane parallel with and intermediate the in Fig. 1. 'At the next instant of time, the cores of the electro-magnet and also intercurrent reversing itself in the circuit, the mediate said magnetic poles whereby the attractive forces at pole 10 is decreased and ends of the armature are subjected simultaat the pole 11 increased so that the opposite efi'ect is had in'.the armature, and the diaphragm 4 is forced to move in the opporeceiverdiaphragm. Y site direction. Every movement of the 3.- In a, telephone receiver, the combinaarmature, however slight, is thus reproduced tion of means for forming two separated in' the diaphragm, and is also multiplied magnetic poles of opposite polarity, an elecbyreason of the leverage exerted through tro-magnet having its cores' forming conmeans for connecting the armature to the a the connecting arm 12. The armature being tinuations of one of said poles, an armature pivoted at its center and subject to the joint placed between the cores and the free end of action of the poles 10 11 of the electro-ma the pole forming means, and having a pivnet 2, exerted at its two ends, the inertia otal support intermediate its ends, the axis of the armature is reduced to a minimum of movement of the armature being in a and the power exerted therein to a maxi plane parallel with and intermediate the mum. The arm 12 and diaphragm 4 are cores of, the electro-magnet and also intervery light'and thus ofler slight resistance to mediate said magnetic poles whereby the the movement, so that a very powerful efends of the armature are subjected simultafeet is produced and the voice currents in neously to oppositely acting forces, springs the c1rcu1t are transformed into sound waves adapted to ijacilitate the responsive movetance from the instrument.

' means, and an armature for said cores havthat are earned through the horn 17 and ments of the armature and means for conmay be heard clearly at a considerable disnecting the armature to the receiver d1a- H phragm.

. Ideal conditlons would be attained were 4. In a telephonereceiver, the combinait possible to provide an armature of large tion of an electro-magnet having parallel mass to permit a large flow of magnetic flux axes and poles permanently magnetized to *therethrough, but without weight, thus the same polarity, aipolarized armature pivavoidlng loss .due to, overcoming inertia. otally mounted in a plane passing between As such ideal conditions are impossible, an the poles of the magnet whereby the armaaTPPIQXI IDatIOII thereto is obtained by so ture maybe turned in one directionby one plvoting the armature as to be practically in pole and in the opposite dlrection by the equilibrium and its ends are'simultaneously other pole and means for forming a mag acted on by magnetic forces operating in netic pole of a polarity opposite that of the opposite directions. poles of the electro-magnet and placed on neously to oppositely acting forces, and.

' Having thus described our invention, we the side of thesaid armature opposite the claim as new and desire to secure by Letters electro-magnet. and adapted to act in con- Iatent the following: l junction with the poles of the electro-mag- 1; In a telephone receiver, the combina net in shifting the armature by simultation of means for forming a magnetic cirneously attracting opposite ends 015 arma- 11i t, an electro-magnet having itscores lyvtures in opposite directions, and means for lng'in said circuit and normally having the connecting the armature to the receiver diapolarity of one pf the members of said phragm, I a l ,5. In a telephone receiver, the combinaingits pivotal support betweenits ends 'and tion of anelectro-magn't h ving parallel so as to lie between the electro-magnet and axes and poles permanently the second member of the meansproducing the same polarity, a polarized armaturepivthe magnetic circuit, whereby as one end of] otal-ly mounted in a. plane passing between the armature is drawn to] one pole. of the the poles'of the magnet whereby the armaelectro magnet on the passageof a current ture may be turned in one direction by one magnetized to its through its coils, the other end bf the arma' pole and in the opposite direction by the ture will be attracted in the opposite direcg tion toward said second member, and means netlc pole of a polarity opposite'that of the poles'of the electro-magnet adapted toact In Witness whereof we hereunto subscibe in conjunction with thepoles of the electrpour names this 8th day of July, A. D. 1910.

magnet on the side of the armature opposite v SERGIU'S P. GRACE.

the electro-magnet in shifting the armature, RICHARD A. L. SNYDER. 5 and a diaphragm connected to .the armature 1 Witnesses: 1

and arranged in' a plane passing through J. F. MOKENNA,-

. the axes of the armature. R. A.. WATT. 

